Low power sensor communication using two or fewer wires

ABSTRACT

A sensor module, in some embodiments, comprises a sensor configured to capture data and a sensor interface coupled to the sensor and configured to process the data captured by the sensor to form processed data. The sensor module may also comprise a current consumption configuration component and a transistor coupled to the current consumption configuration component and configured to control the current consumption configuration component to output the processed data.

BACKGROUND

Sensors that communicate with a processor may be located remotely withrespect to the processor. In some circumstances, these remote locationsmay have limited access to power and may involve high cost for providingelectrical connectivity between the sensor and the processor. Thus, forsome sensors, it may be advantageous to reduce a number of electricalwires providing connectivity between the sensor and the processor. Forsome sensors it may also be advantageous to minimize an amount of powerconsumed by the sensor. Such reduced connections with minimized powerconsumption, however, may be difficult to implement.

SUMMARY

At least some of the embodiments disclosed herein are directed to asensor module, comprising: a sensor configured to capture data; a sensorinterface coupled to the sensor and configured to process the datacaptured by the sensor to form processed data; a current consumptionconfiguration component; and a transistor coupled to the currentconsumption configuration component and configured to control thecurrent consumption configuration component to output the processeddata. Such embodiments may be supplemented in a variety of ways,including by adding any of the following concepts in any sequence and inany combination: wherein the sensor module is configured to couple to aprocessor, and wherein the transistor is configured to control thecurrent consumption configuration component to output the processed datato the processor; wherein the sensor module is further configured todraw a first current magnitude from the processor when the sensorcaptures data and the sensor interface processes the data captured bythe sensor; wherein the sensor module is further configured to coupledirectly to the processor via only one electrical wire, the electricalwire configured to provide power from the processor to the sensor moduleand communicate the processed data from the sensor module to theprocessor; wherein the transistor is configured to control the currentconsumption configuration component to alternate a current draw of thesensor module between the first current magnitude and a second currentmagnitude less than the first current magnitude to communicate theprocessed data to the processor; wherein the first current magnituderepresents a binary one, and wherein the second current magnituderepresents a binary zero; wherein the sensor is an automotive pressuresensor.

At least some of the embodiments disclosed herein are directed to amethod for capturing data and communicating the data from a sensormodule to a processor, comprising: activating a sensor of the sensormodule to capture the data; activating a current source to maintain anapproximately constant current draw of a first current magnitude by thesensor module via a first electrical wire when the sensor is activated,the first electrical wire configured to couple the sensor module to theprocessor to provide power to the sensor module; storing the data;deactivating the sensor after the data is captured and stored; andselectively deactivating and reactivating the current source based on acontent of the stored data to communicate the stored data from thesensor module to the processor via the first electrical wire. Suchembodiments may be supplemented in a variety of ways, including byadding any of the following concepts in any sequence and in anycombination: wherein selectively deactivating and reactivating thecurrent source based on the content of the stored data comprisesdeactivating the current source to communicate a first value of thestored data and reactivating the current source to represent a secondvalue of the stored data; wherein to communicate the stored data fromthe sensor module to the processor, the method further comprises drawinga second current magnitude less than the first current magnitude torepresent the first value and drawing the first current magnitude torepresent the second value; wherein the second current magnitude is anapproximately minimum current draw of the sensor module; whereinselectively deactivating and reactivating the current source comprisescontrolling a transistor to deactivate and reactivate the currentsource; further comprising activating the sensor to capture second dataafter communicating the stored data from the sensor module to theprocessor via the electrical wire; and wherein the first currentmagnitude is approximately 3 milliamps (mA) and the second currentmagnitude is approximately 1 mA.

At least some of the embodiments disclosed herein are directed to asystem, comprising: a processor; and a sensor module coupled to theprocessor and configured to draw a first magnitude of current from theprocessor to capture data, the sensor module comprising: a currentsource; a sensor configured to capture the data; and a transistorconfigured to control the current source to communicate the data fromthe sensor module to the processor, wherein the transistor alternates acurrent draw of the sensor module between the first magnitude of currentand a second magnitude of current. Such embodiments may be supplementedin a variety of ways, including by adding any of the following conceptsin any sequence and in any combination: wherein the second magnitude ofcurrent is less than the first magnitude of current, and wherein, tocommunicate data to the processor, the sensor module draws the firstmagnitude of current to represent a first data value and draws thesecond magnitude of current to represent a second data value; whereinthe first data value is a logical high value and the second data valueis a logical low value; wherein to control the current source, thetransistor selectively activates and deactivates the current source;wherein the sensor is an automobile pressure sensor; and wherein thesensor module is configured to couple to the processor via two or fewerelectrical wires, and wherein the two or fewer electrical wires areselected from the group consisting of: a power supply electrical wireand a ground electrical wire.

BRIEF DESCRIPTION OF THE DRAWINGS

There are disclosed in the drawings and in the following description,various embodiments for communication of data from a sensor to aprocessor when the sensor is coupled to the processor using two or fewerelectrical wires. In the drawings:

FIG. 1 is a conceptual block diagram of an electrical circuit includinga control circuit used for synchronization of a plurality of switchingevents.

FIG. 2 is a block diagram of a sensor module in accordance with variousembodiments.

FIG. 3 is a graph of current consumption by a sensor in accordance withvarious embodiments.

FIG. 4 is a flowchart of a method for capturing data and communicatingthe data from a sensor module to a processor in accordance with variousembodiments.

It should be understood, however, that the specific embodiments given inthe drawings and detailed description thereto do not limit thedisclosure. On the contrary, they provide the foundation for one ofordinary skill to discern the alternative forms, equivalents, andmodifications that are encompassed together with one or more of thegiven embodiments in the scope of the appended claims.

DETAILED DESCRIPTION

Sensors may be used to provide useful data to a processor from locationsremote to the processor. For example, a temperature or precipitationsensor may be located in an environmentally exposed location and may becoupled to a processor that is enclosed within a housing to provide datato the processor. As another example, a pressure sensor in an automobilemay be located proximate to a wheel or tire of the automobile and may becoupled to a processor located elsewhere in the automobile to providedata to the processor. As used herein, a sensor is any electrical and/ormechanical component or combination of components that is suitable forcapturing data and communicating that data to a processor. Also as usedherein, a processor is any form of a processing element such as aprocessor, microprocessor, central processing unit (CPU), an embeddedprocessor, a digital signal processor, digital logic, or any otherelectrical structure suitable for receiving and/or performing operationswith data, such as that communicated by a sensor. A sensor may becoupled to a processor via one or more communication lines (e.g.,electrical wires). As such, use of a sensor may in some embodimentsinvolve a plurality of costs (e.g., a material cost per unit distance ofcommunication line that couples the sensor to the processor and a powercost for the amount of available power in a system that is consumed bythe sensor to capture and/or communicate data). In some systems (e.g.,systems in which power is limited or is considered to have a high cost)it may be desirable to minimize an amount of current consumed by asensor when capturing data and/or communicating data to a processor. Itmay also be desirable to minimize an amount of material cost associatedwith use of a sensor by minimizing a quantity of communications linesthat couple the sensor to the processor.

Disclosed herein are embodiments for communicating data from a sensor toa processor. More precisely, at least some embodiments are directed tocommunicating data from a sensor to a processor at low power when thesensor is coupled to the processor via two or fewer couplings. At leastsome of the disclosed embodiments may provide for a sensor communicatingdata to a processor while consuming a current magnitude approximatelyequal to or less than a current magnitude utilized by the sensor tocapture data. For example, in some embodiments the sensor may capturedata and communicate that data to the processor within a 3 mA currentlimit. At least some of the disclosed embodiments may also provide for asensor communicating data to a processor when the sensor is coupled tothe processor by two or fewer communication lines. For example, in someembodiments the sensor may communicate data to the processor on a powerline when the sensor is coupled to the processor via two communicationlines (e.g., a power or source line used by the sensor to draw amagnitude of current from the processor for operation of the sensor anda ground line). As another example, in some embodiments the sensor maycommunicate data to the processor on a power line when the sensor iscoupled to the processor via one communication line (e.g., a power orsource line) and coupled to a common ground plane to which the processoris also coupled (e.g., a metal surface of an automobile that is coupledto a ground supply when the sensor and the processor are utilized in anautomobile). The sensor may, in some embodiments, communicate the datato the processor on the power line by varying a current magnitude drawnby the sensor from the processor (e.g., varying the current magnitudedrawn by the sensor based on a plurality of values or levelscorresponding to digital logic levels or other predefined values).

FIG. 1 is a block diagram of a system 100 including a sensor module 110and a processor 120 in accordance with various embodiments. The sensormodule 110 may be coupled to the processor 120 via a power communicationline 130. The sensor module 110 may optionally also be coupled to theprocessor 120 via a ground communication line 140 such that the sensormodule 110 is directly coupled to the processor 120 via two couplings.Alternatively, the sensor module 110 may optionally be coupled to acommon ground plane 150 to which the processor 120 is also optionallycoupled such that the sensor module 110 is directly coupled to theprocessor 120 via only one coupling. As used herein, a direct couplingbetween generic representative components A and B may indicate acoupling exclusively between component A and component B with no otherintervening components. For example, a direct coupling, in someembodiments, may be characterized by an electrical wire coupling at afirst end to component A and at a second end to component B. Conversely,an indirect coupling between components A and B may indicate thatcomponents A and B are coupled through an intermediary component towhich both component A and component B are individually, directly orindirectly, coupled. For example, an indirect coupling, in someembodiments, may be characterized by component A and component B eachcoupling individually, directly or indirectly, to a common ground plane.

The processor 120 may provide power (e.g., a voltage magnitude and acurrent magnitude) to the sensor module 110 via the power communicationline 130. The voltage magnitude and/or current magnitude may bedetermined with respect to the ground communication line 140, or thecommon ground plane 150, depending on which source of a ground referenceis utilized in the system 100. The current magnitude provided by theprocessor 120 to the sensor module 110 may be determined, in someembodiments, by a current magnitude drawn by the sensor module 110 andconsumed during operation of the sensor module 110. The sensor module110 may be configured to draw an approximately constant currentmagnitude from the processor 110 during data capture operations of thesensor module 110. The sensor may be further configured to communicatedata to the processor 120 by manipulating the current magnitude drawn bythe sensor module 110 during data communication operations of the sensormodule 110. For example, the sensor may be configured to consume anapproximately constant X mA during data capture operations. Whencommunicating data, the sensor module 110 consuming approximately X mAmay be interpreted by the processor 120 as a logic-level high value(e.g., a digital “1”) and the sensor module 110 consuming approximatelyX-Y mA may be interpreted by the processor 120 as a logic-level lowvalue (e.g., a digital “0”), where Y is a predefined gap between thelogic-level high value and the logic-level low value. For example, thesensor 120 consuming approximately 3 mA when communicating data may beinterpreted as a logic-level high and the sensor 120 consumingapproximately 1 mA when communicating data may be interpreted as alogic-level low. In this way, the sensor module 110 may communicate datato the processor 120 by manipulating the current magnitude consumed bythe sensor module 110.

The values X and Y may be any suitable current magnitudes that result ina desired operation of the sensor module 110. In addition, while thesensor module 110 is discussed above as indicating two separate values(e.g., a logic-level high value and a logic-level low value), the sensormodule 110 may be configured to indicate any number of levels bymanipulating the current magnitude drawn by the sensor module 110 duringdata communication operations of the sensor module 110. For example, thesensor module 110 may be configured to indicate three values, fourvalues, five values, and so forth by manipulating the current magnitudedrawn by the sensor module 110 during data communication operations ofthe sensor module 110 according to predetermined or predefined levelsknown to the processor 120.

Additionally, by communicating with the processor 120 via the powercommunication line 130, the sensor module 110 may, in some embodiments,reduce a cost associated with providing data to the processor 120 incomparison with conventional sensor implementations that do notcommunicate data to a processor via a power communication line. Forexample, communicating data from the sensor module 110 to the processor120 via the power communication line 130 in place of a separate ordedicated data communication line may, in some embodiments, reduce acost associated with providing data from the sensor module 110 to theprocessor 120 by making a dedicated data communication line unnecessaryand/or redundant with the power communication line 130.

FIG. 2 is a block diagram of a sensor module 200 in accordance withvarious embodiments. The sensor module 200 may be implemented, in someembodiments, as a sensor module 110, as discussed above, to capture dataand communicate the data to a processor, such as the processor 120. Thesensor module 200 may include a front end 210, a sensor 220, a sensorinterface 230, a plurality of transistors (e.g., transistors 240A, 240B,240C, and 240D), and a current source 250. The front end 210 maycomprise a plurality of electrical components that may be configured tosupport operation of the sensor module 200. For example, the front end210 may comprise one or more voltage regulators, one or more datastorage components (e.g., digital logic structures capable of storingdata measured by the sensor 220 and/or processed by the sensor interface230), one or more reference voltage generators, and/or any otherelectrical components that may support operation of the sensor module200. The front end 210 may be coupled directly or indirectly to thesensor 220, the sensor interface 230, any of the transistors 240A, 240B,240C, or 240D, and/or the current source 250. For example, the front end210 may be coupled to the transistor 240A to control the transistor 240A(e.g., such that the transistor 240A may function in a mannersubstantially similar to that of a switch) to control a flow of power tothe sensor 220 and the sensor interface 230. The front end 210 may alsobe coupled to the transistor 240B to control the transistor 240B tocontrol a flow of power to the current source 250.

The sensor 220 may be any sensor capable of capturing and outputting anelectrical signal based on one or more mechanical or electricalmeasurements (e.g., related to an area or condition proximate to thesensor 220), a type of which is not limited herein. For example, thesensor 220 may be a digital sensor, an analog sensor, or a combinationof both, and may be, for example, a Wheatstone bridge, a pressuresensor, a temperature sensor, a position sensor (e.g., GlobalPositioning Satellite (GPS) or other position determining sensor), analtitude sensor, a moisture sensor, or other like sensor that maycapture data related to an area or condition proximate to the sensors.The sensor 220 may be coupled to one or more of the front end 210, thesensor interface 230, and/or other electrical components that supportoperation of, or interact with, the sensor 220. As such, in someembodiments, the sensor 220 may capture the data and transmit the datato a data storage component (e.g., digital logic structures of the frontend 210) to store the data for later transmission, processing, or otherforms of use. In other embodiments, the sensor 220 may capture the dataand transmit the data to the sensor interface 230. The sensor interface230 may include one or more electrical components configured to process,manipulate, or otherwise interact with data received from the sensor 220to form processed data that is based on the data received from thesensor 220. The one or more electrical components of the sensorinterface 230 are not limited herein, but may include, for example, anyone or more of an analog to digital converter (ADC), a digital to analogconverter (DAC), an amplifier, a filter, digital signal processingcircuitry, analog signal processing circuitry, or other electricalcomponents that may be suitable for interacting with the data receivedfrom the sensor 220. The sensor interface 230 may be coupled to thefront end 210 and configured to transmit the processed data to one ormore electrical components of the front end 210 (e.g., digital logicstructures of the front end 210) for data storage after processingand/or prior to transmission from the sensor module 200 to anotherelectrical component (e.g., a processor).

The front end 210 may be configured to transition the sensor 220 and thesensor interface 230 to a low power mode when the sensor 220 is notcapturing data and/or when the sensor interface 230 is not processingdata received from the sensor 220 to, for example, configure the sensormodule 200 to draw an approximately minimum magnitude of current fromthe processor. The minimum magnitude of current drawn by the senormodule 200 from the processor may be defined, in some embodiments, as aminimum magnitude of current that may be drawn by the sensor module 200when the sensor module 200 is powered, but is not capturing and/orprocessing data (e.g., when only the front end 210 is drawing currentfrom the processor). The front end 210 may transition the sensor 220 andthe sensor interface 230 to the low power mode, in some embodiments, bytransmitting a voltage magnitude to the transistor 240A that isinsufficient to cause the transistor 240A to permit a flow of power(e.g., a flow of electrons through the transistor 240A) to the sensor220 or the sensor interface 230, thereby effectively uncoupling thesensor 220 and sensor interface 230 from the circuit of the sensormodule 200. The front end 210 may transition the sensor 220 and thesensor interface 230 to the low power mode to enable the sensor module200 to communicate data from the sensor module 200 (e.g., data stored indigital logic structures of the front end 210) to another electricalcomponent (e.g., a processor). Transitioning the sensor 220 and thesensor interface 230 to the low power mode may enable the sensor module200 to communicate data at a magnitude of power consumptionapproximately equal to, or less than, a magnitude of power consumedwhile the sensor 220 is capturing data and/or the sensor interface 230is processing the data received from the sensor 220.

Once in the lower power mode, the sensor module 200 may communicate datato another electrical component (e.g., such as a processor, as used inthe following discussion for the sake of clarity). The sensor module 200may communicate data (e.g., data captured by the sensor 210 and/or dataprocessed by the sensor module 220), in some embodiments, from a datastorage component (e.g., a digital logic structure) that may be locatedin the front end 210. The data may be communicated by, for example,controlling and/or manipulating a current magnitude drawn by the sensormodule 200 from the processor. For example, the processor may monitor acurrent magnitude drawn by the sensor module 200. Because the sensormodule 200 may be configured to draw an approximately constant currentmagnitude from the processor when the sensor module 200 is notcommunicating data, if the current magnitude drawn by the sensor module200 decreases for a predefined period of time, the processor, in someembodiments, may interpret the decrease in current magnitude drawn as anindication that the sensor module 200 is commencing communication ofdata.

When the processor determines that the sensor module 200 has commencedcommunicating data, the processor may sample the current magnitude drawnby the sensor module 200 at predefined intervals until the processordetermines that the sensor module 200 has stopped communicating data(e.g., based on a stop indication transmitted by the sensor module 200).Each sample of the current magnitude drawn by the sensor module 200 maycorrespond to a data point of the data being communicated by the sensormodule 200. For example, after the processor determines that the sensormodule 200 has commenced communicating data, the processor may samplethe current magnitude drawn by the sensor module 200 at a first time toreceive a first value of the data being communicated by the sensormodule 200 and may sample the current magnitude drawn by the sensormodule 200 at a second time to receive a second value of the data beingcommunicated by the sensor module 200. As such, the sensor module 200may be configured to draw the approximately constant current magnitudeto represent the first value of the data being communicated by thesensor module 200 and may be configured to draw the approximatelyminimum current magnitude to represent the second value of the databeing communicated by the sensor module 200. Accordingly, in someembodiments, the sensor module 200 may be configured to communicate dataat a magnitude of current consumption less than, or equal to, amagnitude of current consumed in acquiring and/or processing the databeing communicated. Alternatively, the sensor module 200 may beconfigured to represent any number of predefined values based on anypredefined current magnitude drawn by the sensor module 200 from theprocessor. For example, the sensor module 200 may be configured torepresent binary values, analog values, or any other suitable valuesbased on the current magnitude drawn by the sensor module 200 from theprocessor. Generally, the sensor module 200 may communicate data to theprocessor by manipulating a current draw of the sensor module 200 amongany number of predefined current magnitudes that are mapped topredefined values known to both the sensor module 200 and the processor,and a number of mappings or predefined values is not limited herein. Forexample, in some embodiments, the sensor module 200 may communicate thedata to the processor by manipulating the current draw of the sensormodule 200 between 3 mA and 1 mA.

The sensor module 200 may manipulate the current magnitude drawn fromthe processor during the low power mode by selectively activating ordeactivating the current source 250. While current source 250 isillustrated as a single current source having one value, any number ofcurrent sources of predefined magnitudes, as discussed above for thecommunication of a corresponding number of predefined data values, maybe placed in parallel and selectively activated or deactivated tocommunicate a respective data value from the sensor module 200. Thecurrent source 250 may be selectively activated and deactivated, in someembodiments, by coupling or uncoupling the current source 250 from thecircuit of the sensor module 250, for example, via a mechanical switch(e.g., a relay) or a solid-state component (e.g., a transistor)functioning as an electrical switch. Alternatively, in some embodiments,the sensor module 200 may include a current consumption configurationcomponent in place of, or in addition to, the current source 250. Thecurrent consumption configuration component may be any one or moreelectrical components (e.g., directly and/or indirectly coupled inseries and/or parallel) that may affect the current magnitude drawn bythe sensor module 200 from the processor. For example, in someembodiments, the current consumption configuration component may be oneor more resistors or other electrical components that may be selectivelyactivated and deactivated (or switched into, and out of, the circuit ofthe sensor module 200) to affect the current magnitude drawn by thesensor module 200 from the processor.

The sensor module 200 may be configured to draw the approximatelyconstant current magnitude from the processor based, at least in part,on the current source 250. For example, in some embodiments the currentsource 250 may be a reference current used to regulate currentconsumption (e.g., current drawn by the sensor module 200 from theprocessor) of the sensor module 200. For example, the transistor 240A(which may have a transistor width, in some embodiments, ofapproximately 100 units) may be controlled by the front end 210, asdiscussed above, to effectively couple or uncouple the sensor 220 andthe sensor interface 230 from the circuit of the sensor module 200(e.g., to transition the sensor module to, or from, the low power mode).As such, a current flowing through the transistor 240A may beapproximately equal to a total current drawn by the sensor 220 and thesensor interface 230. The transistor 240B may, in some embodiments, havea transistor width of approximately 1 unit such that approximately 1/100of the current that flows through the transistor 240A will flow throughthe transistor 240B. As such, the transistor 240B may sense a currentmagnitude used by the sensor module 200 to capture and/or process data(e.g., by the sensor 220 and/or the sensor interface 230). As such, thecombination of the sensor 220, the sensor interface 230, the transistor240A, and the transistor 240B may consume a magnitude of currentapproximately equal to 101 times the total current drawn by the sensor220 and the sensor interface 230.

The transistor 240C may, in some embodiments, have a transistor width ofapproximately 1 unit and may determine a difference between the currentsensed by the transistor 240B and the reference current of currentsource 250. For example, a current flowing through the transistor 240Cmay approximately equal a difference between the reference current ofcurrent source 250 and the current sensed by the transistor 240B. Thetransistor 240D may, in some embodiments, have a transistor width ofapproximately 100 unit and may be configured to multiply the currentflowing through the transistor 240C by approximately 100 (e.g., as aresult of the ratio of transistor widths of the transistor 240D to thetransistor 240C). As such, the combination of the transistor 240C andthe transistor 240D may consume a magnitude of current approximatelyequal to 101 times the reference current of current source 250. Each ofthe transistors 240A, 240B, 240C, and 240D may, in some embodiments, bep-type metal oxide semiconductor field effect transistors (MOSFETs).Alternatively, in other embodiments, the transistors 240A, 240B, 240C,and 240D may each be constructed according to another suitablemethodology or process, and the configuration the circuit of the sensormodule 200 may be modified accordingly. Additionally, while each of thetransistors 240A, 240B, 240C, and 240D are illustrated as p-typeMOSFETs, in some embodiments the transistors 240A, 240B, 240C, and 240Dmay include transistors constructed according to a plurality ofmethodologies or processes. Additionally, the widths of the transistors240A, 240B, 240C, and 240D are expressed in terms of generic units thatmay vary based on a type of process used to construct the transistors240A, 240B, 240C, and 240D (e.g., a micrometer process, a nanometerprocess, etc.).

The configuration of the transistors 240A, 240B, 240C, and 240D and thecurrent source 250 illustrated in FIG. 2 and described above may, insome embodiments, enable a maximum current consumption of the sensormodule 200 to be programmed or predetermined according tocharacteristics of the current source 250. For example, based on theconfiguration of the transistors 240A, 240B, 240C, and 240D and thecurrent source 250, the current consumption of the sensor module 250 maybe determined without respect to the sensor 220 or the sensor interface230, which may have fluctuating current consumptions over time, load,temperature, etc. As such, a magnitude of the reference current of thecurrent source 250 may be selected to be greater than a maximum totalcurrent drawn by the sensor 220 and the sensor interface 230 such thatthe current consumption of the sensor module 200 when capturing and/orprocessing data in the active state (e.g., when not in low power mode)is approximately constant based on the current source 250.

While the sensor module 200 illustrates one possible configuration ofelectrical circuit components suitable for implementing at least some ofthe disclosed embodiments, other configurations of circuitry that mayprovide a same or similar functionality are also intended to be includedwithin the scope of the present disclosure. For example, embodiments inwhich the sensor module 200 maintains an approximately constant currentdraw from a processor (e.g., which serves as a power source or powersupply for the sensor module 200) based on another configuration ofelectrical circuit components are also intended to be included withinthe scope of the present disclosure.

FIG. 3 is a graph 300 of current consumption by a sensor in accordancewith various embodiments. For example, in some embodiments the graph 300may be representative of current consumption (e.g., a current magnitudedrawn) by the sensor module 200. A horizontal axis of the graph 300 maybe representative of time (e.g., seconds, microseconds, picoseconds,nanoseconds, etc.) and a vertical axis of the graph 300 may berepresentative of current (e.g., amps, milliamps, microamps, etc.) drawnby the sensor. During the period of time indicated by T1, the sensor maybe in an active state (e.g., capturing data and/or processing captureddata). When the sensor has finished capturing and/or processing data, insome embodiments, the data may be stored to a data store during theactive state. As illustrated by graph 300, the sensor may draw anapproximately constant current magnitude from a processor (e.g., theprocessor 110) during the active state (e.g., a max current). Forexample, during the active state, the sensor may, in some embodiments,draw approximately 3 mA of current from the processor.

After the sensor captures and/or processes and saves data in the activestate, the sensor may be transitioned to a low power state in which oneor more components of the sensor are uncoupled from a power supply, asdiscussed above. For example, one or more components of the sensor maybe uncoupled from the power supply such that the sensor may drawapproximately a minimum current magnitude from the processor. Forexample, during the period of time T2, the sensor may be transitionedfrom the active state to the low power state. In some embodiments, theminimum current magnitude drawn by the sensor from the processor may beapproximately 1 mA.

During the time period T3, the sensor may communicate data to theprocessor via a power supply line coupling the sensor to the processor.For example, the sensor may communicate data by manipulating the currentmagnitude drawn by the sensor to represent values of the data stored bythe sensor, as discussed above. At the beginning of the time period T3,the sensor may draw the minimum current magnitude from the processor fora predefined period of time to indicate to the processor thatcommunication of data from the sensor is commencing. The predefinedperiod of time may be any suitable period of time known to both thesensor and the processor, a duration of which is not limited herein.During the time period T3, the sensor may manipulate the currentmagnitude drawn by the sensor between the constant current drawn duringthe active state (e.g., to represent a first value of the stored datasuch as a logic-level high value or binary “one”) and the minimumcurrent magnitude (e.g., to represent a second value of the stored datasuch as a logic-level low value or binary “zero”). At the conclusion ofthe stored data being transmitted or communicated by the sensor to theprocessor, the processor may draw the minimum current magnitude from theprocessor for a predefined period of time to indicate to the processorthat communication of data from the sensor is concluded. The predefinedperiod of time may be any suitable period of time known to both thesensor and the processor, a duration of which is not limited herein, andmay be approximately the same as, or different than, the predefinedperiod of time that indicates communication of data from the sensor iscommencing.

During the time period T4, after communicating the data to theprocessor, the sensor may transition from the low power state to theactive state by recoupling the previously uncoupled components to thepower supply. Once the sensor is in the active state at the conclusionof the time period T4, the sensor may repeat its process of capturingdata, processing and storing the data, and communicating the data. Forexample, at the conclusion of the time period T4 the sensor may repeatits process as discussed above, beginning with the time period T1, suchthat the time periods T1, T2, T3, and T4 form a sequential series thatis executed by the sensor in a loop.

FIG. 4 is a flowchart of a method 400 for capturing data andcommunicating the data from a sensor module to a processor in accordancewith various embodiments. The method 400 may be performed by a sensormodule, such as sensor module 200, that is configured to capture andcommunicate data. At step 410, the sensor module may activate a sensorof the sensor module to capture the data. For example, the sensor modulemay activate the sensor by controlling a transistor to cause thetransistor to allow a flow of current to the sensor from a processor.Optionally, after capturing the data, the sensor module may processand/or manipulate the data using a sensor interface. At step 420, thesensor module may activate a current source to maintain an approximatelyconstant current draw of a first current magnitude by the sensor module.It should be noted that step 420 may, in some embodiments, be performedprior to, or approximately concurrently with, step 410. The sensormodule may draw the approximately constant current draw of the firstcurrent magnitude via a first electrical wire that may couple the sensormodule to a processor to, at least, provide power to the sensor modulefrom the processor.

At step 430, the sensor module may store the data captured by the sensorand/or processed by the sensor interface. For example, the sensor modulemay store the data in one or more data stores (e.g., the digital logicstructures of the front end 210, discussed above) to enable the sensormodule to communicate (e.g., transmit and/or output) the data at a latertime and/or when the sensor and/or sensor interface are uncoupled fromthe processor. At step 440, after the data is captured and stored, thesensor module may deactivate the sensor. The sensor module maydeactivate the sensor, in some embodiments, to enter a low power mode,as discussed above. The sensor module may deactivate the sensor, forexample, by controlling a transistor to cause the transistor to inhibita flow of current to the sensor from the processor.

At step 450, the sensor module may selectively deactivate and reactivatethe current source based on the data stored at step 430 to communicatethe stored data. The sensor module may communicate the stored data tothe processor via the first electrical wire such that the firstelectrical wire may also couple the sensor module to the processor tocommunicate data from the sensor module to the processor. The sensormodule may selectively deactivate and reactivate the current source torepresent values of the data stored at step 430, for example, such thata first value of the stored data is represented by the current sourcebeing activated and a second value of the stored data is represented bythe current source being deactivated. For example, in some embodimentsthe first value may be a logical “one” and the second value may be alogical “zero.” The sensor module may selectively deactivate andreactivate the current source, in some embodiments, by controlling atransistor to inhibit or allow, respectively, a flow of current to orfrom the current source. In some embodiments, the sensor module mayconsume approximately 3 mA of current when the current source isactivated and may consume approximately 1 mA of current when the currentsource is deactivated. In some embodiments, after the sensor module mayselectively deactivates and reactivates the current source based on thedata stored at step 430 to communicate the stored data, the method mayfurther include reactivating the sensor for capturing second data, forexample, by returning to step 410 to repeat the method 400.

Numerous other variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations, modifications and equivalents. Unless otherwise stated,“approximately” means +/−10 percent of the stated value or of areference value. In addition, the term “or” should be interpreted in aninclusive sense.

What is claimed is:
 1. A sensor module, comprising: a sensor configuredto capture data; wherein the sensor module is configured to couple to aprocessor; a sensor interface coupled to the sensor and configured toprocess the data captured by the sensor to form processed data; acurrent consumption configuration component; and a transistor, coupledto the current consumption configuration component and to the sensor,configured to control the current consumption configuration component tooutput the processed data to the processor.
 2. The sensor module ofclaim 1, wherein the sensor module is further configured to draw a firstcurrent magnitude from the processor when the sensor captures data andthe sensor interface processes the data captured by the sensor.
 3. Thesensor module of claim 2, wherein the sensor module is furtherconfigured to couple directly to the processor via only one electricalwire, the electrical wire configured to provide power from the processorto the sensor module and communicate the processed data from the sensormodule to the processor.
 4. The sensor module of claim 2, wherein thetransistor is configured to control the current consumptionconfiguration component to alternate a current draw of the sensor modulebetween the first current magnitude and a second current magnitude lessthan the first current magnitude to communicate the processed data tothe processor.
 5. The sensor module of claim 4, wherein the firstcurrent magnitude represents a binary one, and wherein the secondcurrent magnitude represents a binary zero.
 6. The sensor module ofclaim 1, wherein the sensor is an automotive pressure sensor.
 7. Amethod for capturing data and communicating the data from a sensormodule to a processor, comprising: activating a sensor of the sensormodule to capture the data; activating a current source to maintain anapproximately constant current draw of a first current magnitude by thesensor module via a first electrical wire when the sensor is activated,the first electrical wire configured to couple the sensor module to theprocessor to provide power to the sensor module; storing the data;deactivating the sensor after the data is captured and stored; andselectively deactivating and reactivating the current source based on acontent of the stored data to communicate the stored data from thesensor module to the processor via the first electrical wire, whereinselectively deactivating and reactivating the current source comprisescontrolling a transistor coupled to the current source and configured tocontrol the current source to communicate the data from the sensormodule to the processor.
 8. The method of claim 7, wherein selectivelydeactivating and reactivating the current source based on the content ofthe stored data comprises deactivating the current source to communicatea first value of the stored data and reactivating the current source torepresent a second value of the stored data.
 9. The method of claim 8,wherein to communicate the stored data from the sensor module to theprocessor, the method further comprises drawing a second currentmagnitude less than the first current magnitude to represent the firstvalue and drawing the first current magnitude to represent the secondvalue.
 10. The method of claim 9, wherein the second current magnitudeis an approximately minimum current draw of the sensor module.
 11. Themethod of claim 7, further comprising activating the sensor to capturesecond data after communicating the stored data from the sensor moduleto the processor via the electrical wire.
 12. The method of claim 7,wherein the first current magnitude is approximately 3 milliamps (mA)and the second current magnitude is approximately 1 mA.
 13. A system,comprising: a processor; and a sensor module coupled to the processorand configured to draw a first magnitude of current from the processorto capture data, the sensor module comprising: a current source; asensor configured to capture the data; and a transistor configured tocontrol the current source to communicate the data from the sensormodule to the processor, wherein the transistor alternates a currentdraw of the sensor module between the first magnitude of current and asecond magnitude of current.
 14. The system of claim 13, wherein thesecond magnitude of current is less than the first magnitude of current,and wherein, to communicate data to the processor, the sensor moduledraws the first magnitude of current to represent a first data value anddraws the second magnitude of current to represent a second data value.15. The system of claim 14, wherein the first data value is a logicalhigh value and the second data value is a logical low value.
 16. Thesystem of claim 13, wherein to control the current source, thetransistor selectively activates and deactivates the current source. 17.The system of claim 13, wherein the sensor is an automobile pressuresensor.
 18. The system of claim 13, wherein the sensor module isconfigured to couple to the processor via two or fewer electrical wires,and wherein the two or fewer electrical wires are selected from thegroup consisting of: a power supply electrical wire and a groundelectrical wire.